The main objectives of the NCO are to provide a service to the NNTC which will: (1) maintain and expand the centralized inventory database on a secure network server that contains unidentifiable patient-related clinical information (such as: cognitive status, drug use history, neuropsychology history, CD4 count) and general demographics, pathological data, specimen inventory, and researcher's requests;(2) maintain and monitor a password-protected website accessible to authorized users;(3) serve as an information conduit between the consortium and the public, producing appropriate public relations materials on behalf of the NNTC, including maintaining and updating a public NNTC website, and providing toll free telephone access by which researchers can contact the NCO;(4) collect requests from researchers for specimens, distribute requests to individual NNTC sites, coordinate the shipments of samples, and follow-up on receipt of tissue and fluid delivery;and (5) train NNTC staff in any new database entry methods as a result of approved changes in current database operation and, more specifically, provide them with technical assistance related to data transfer.